Predicting natural ventilation flows in whole buildings. Part 1: The Viipuri Library

Abstract

For energy efficient restoration of historical buildings, especially historic monuments of international importance such as the Viipuri Library by Alvar Aalto (1898 -1976), new analytical tools are needed. Of interest to this research is the evaluation of air movement within this building due to spatial composition, which can also prove very useful in helping architects determine how best to renovate and restore historical buildings. The objective is to analyze how radiant heating and passive cooling are currently exploited in the Viipuri Library. The knowledge will be useful to restore this historical building to function efficiently while ensuring that the existing mechanical ventilation systems and natural convective flows work well together after restoration. Computational fluid dynamics will be used to model, simulate and predict multiple environmental conditions to examine spatial layout effects on the ability of natural ventilation to maintain a comfortable thermal environment and acceptable rates of ventilation. The preliminary results demonstrate that airflow and thermal effects can be predicted and validated for any set of conditions, such as specifying which windows or doors are open, and the ambient conditions exterior (e.g., wind and air temperature) and interior (e.g., radiant pipes) to the building. Keywordscomputational fluid dynamics, energy efficiency, free flow open space, natural ventilation,

Predicting natural ventilation flows in whole buildings. Part 2: The Esherick House

“…As presented in Part I of this paper (Stoakes et al 2011), natural ventilation can significantly reduce the heating and cooling energy requirements of a building. A large portion of energy consumption is used to mechanically condition buildings either through heating or cooling of indoor air.…”

“…The commercial software FLUENT 6.3 (2006) was used to perform all simulations and an overview of the models and types of boundary conditions as applied to this study were presented in Part I (Stoakes et al 2011). The three-dimensional equations solved include conservation of mass, momentum and energy by incorporating a Boussinesq approximation and the standard k-ε turbulence equations.…”

“…An acceptable grid resolution was determined by using the study of Schaelin et al (1992), as discussed in Part I (Stoakes et al 2011). All simulations in the current study are time dependent and time is discretized using a first order implicit method.…”

“…As demonstrated in Part I (Stoakes et al 2011), the commercial CFD software FLUENT is a useful tool to model airflow and temperature fields, and to examine the effectiveness of natural ventilation to control thermal comfort. When exploiting natural ventilation in a building, air velocity must be considered as a variable for human thermal comfort.…”

High Fidelity CFD Modeling of Natural Ventilation in a Solar House

“…There is some CFD modeling that has been used in full-scale buildings to study interior natural ventilation. Stokes et al used CFD to predict natural ventilation flow in a historical building, the Viipuri Library, with the purpose of assisting in the renovation and restoration of the mentioned building [11]. The authors also modeled natural ventilation for different weather conditions in the Esherick House [12], a single-room house whose architectural design provides natural ventilation and lightning.…”